In some cases, effects of gravity may adversely affect an experimental or industrial process. In such cases, it is often desirable to perform the process in a microgravity environment. When a system is in a microgravity environment, all components of the system are subject to identical or indistinguishable gravitational forces. For example, the system may be in free fall or in orbit about a massive body. In such cases, a gravitational contact force between two components of the system, or weight, is absent or practically negligible.
When the process does not require more than a few seconds of microgravity, the process may be performed in a drop tower or similar facility. Slightly longer processes, e.g., that require no more than about half a minute of continuous microgravity, may be performed aboard aircraft that fly in an appropriate pattern (e.g., parabolic arcs). Processes that require longer periods of microgravity (e.g., hours, days, or longer) may be performed aboard unmanned or manned spacecraft. Typically systems that perform processes under microgravity conditions are closed, so as not to allow any materials within the system to escape.
In some cases, a system for performing the process in microgravity may utilize lab-on-a-chip technology or other micro-technology. Use of such technology may enable incorporation of the microgravity system in a platform where available space may be very limited or expensive.
Some such processes require rehydration of powder. Typically such processes are not handled and operated by humans, and therefore require an automated system to perform the process. For example, in U.S. Pat. No. 6,349,850 (Cheikh), there was disclosed a device and method for dehydrating powder that includes a gas-tight syringe to condition under vacuum a dry form of an active principle, a reservoir containing a liquid and a cap forming a connector between the syringe and the liquid reservoir. The injection needle of the syringe is configured to be driven into the septum of the cap. After activation, the extemporaneous preparation is automatic since the device elements move by themselves under the action of the liquid which is drawn by suction into the volume under vacuum containing the solid formulation.